1. Technical Field
The present disclosure relates to an optical encoder, crown assembly and wearable device having an optical navigation chip, and in particular, to a microminiaturization optical navigation chip, an optical navigation module having the optical navigation chip and an optical encoder.
2. Description of Related Art
Following the technology, more and more electronic devices have an optical navigation function. An optical encoder having the optical navigation function is usually disposed with an optical navigation chip to perform the optical navigation function. For example, the most common optical encoder is an optical mouse.
The conventional optical mouse usually includes a light-emitting unit and the optical navigation chip. The light-emitting unit is configured for operatively providing a light beam to irradiate an object (such as a desktop). The optical navigation chip includes a sensing array. The sensing array is disposed corresponding to a surface of the object for receiving a reflected light beam reflected by the surface and capturing an image belonging to a part of the surface once every capturing interval. The optical mouse compares the images and calculates a displacement between a current position and a previous position of the optical mouse.
If the light-emitting unit does not include an optical lens, such as a condensing lens, the light beam provided by the light-emitting unit would scatter easily, such that the light beam has a low light-intensity. Then, there are discrepancies between the image captured by the sensing array and the actual image. Hence, the light-emitting unit usually comprises an optical lens disposed on a light-emitting port to focus the light beam. Moreover, in order to increase image clarity of the images captured by the sensing array, there is also an optical lens disposed on the sensing array to focus the reflected light beam.
However, as in the above descriptions, the conventional optical encoder needs the optical lenses to focus the light beam, such that a size of the optical encoder increases. It is difficult to simultaneously achieve high accuracy and microminiaturization for the optical encoder. Further, the conventional optical encoder only detects the displacement between a current position and a previous position of the optical mouse, so that a rotational movement and a brightness variation are unable to be detected.